Trident Aggregations
In addition to functions and filters, Trident defines a number of aggregator interfaces that allow topologies to combine tuples.
There are three types of Trident aggregators:
-
CombinerAggregator
-
ReducerAggregator
-
Aggregator
As with functions and filters, Trident aggregations are applied to
streams via methods in the Stream class, namely aggregate()
,
partitionAggregate()
, and
persistentAggregate()
.